San Diego, California (CNN) -- Beltway pundits tell us that the main obstacle to Republican primary voters falling in love with undeclared presidential candidate Mitt Romney is that, as governor of Massachusetts, Romney signed into law a health care bill that resembles "ObamaCare."

That is the wrong diagnosis for what ails Romney, who is very likely preparing to run for the Republican presidential nomination. The real affliction isn't that conservatives find it easy to relate the 2006 health care law in Massachusetts with its federal counterpart. Much more troubling for Romney is something you hear very little about: He can't seem to relate to conservatives--and they can't relate to him.

Now, there's no question that health care matters. And it's likely to matter a lot more the more people talk about it. Many Americans probably couldn't tell you what is in either law, but they know conflict and dissension in the ranks when they see it.

And Romney is not doing himself any favors by trying to put the issue to rest, as he attempted in a speech last week in Michigan. The more he tries to prove that the Massachusetts law is different from ObamaCare, the more alike the two sound. Both laws require people to buy health insurance, for instance.

Romney is catching flak from the right, both for signing the bill and for defending it to this day. For those Republicans who were looking forward to running against ObamaCare in the 2012 presidential election, and making that a major pillar of the GOP platform, Romney's history with health care complicates the narrative. Conservatives want Romney to say the Massachusetts bill was a mistake, and he was wrong to sign it.

Romney won't do that, either because he honestly believes that the state law was the right thing to do or because he realizes that such an about-face would come across as the ultimate "flip-flop" and doom his campaign.

And yet, the health care flap isn't the only reason that Republican voters are just not that into Romney. Consider an interview he gave a few weeks ago to a radio show in San Diego.

Appearing on The Mark Larson Show, Romney -- who owns a home in San Diego County -- was hitting softballs out of the park until the host unintentionally knocked him over with a blunt and insightful question. Larson asked Romney why he thought it was that so many people who might otherwise agree with his positions saw him as unapproachable and difficult to relate to.

Romney didn't know how to answer. And, after stammering for a few seconds, he abruptly changed the subject. He obviously hated the question.

I've thought about that interview and filtered it back through most of what we learned about Romney in the 2008 campaign. This is exactly his problem, and it's a major reason why the Tea Party voters who will have a big say in determining who the GOP nominee is next year are having such difficulty warming up to Romney.

Romney is the co-founder of Bain Capital, a private equity investment firm. This is a smart and capable fellow with two Harvard degrees, a golden resume, and an estimated net worth in the neighborhood of $200 million. But who says that kind of portfolio will be an asset next year? It could be a liability if the economy doesn't improve.

Romney is not the guy next door; he's more like the guy who owns the deed to your house and keeps threatening to foreclose. He's not the person holding a placard at a Tea Party rally; he's the boss that the placard guy had to lie to in order to get the day off so he could join the protest. He's not a person who -- you knew this was coming -- you want to have a beer with, or even a glass of chardonnay. Of course, we are speaking figuratively here: Romney is a Mormon and does not drink alcohol.

Funny thing about the beer standard. Everyone likes to mock the idea that Americans would pick a president based on who they feel comfortable with, who they can relate to, and who they'd want to spend time with. Until it works in their favor.

Liberals were furious when Americans twice elected the likable George W. Bush. But, interestingly, they had less trouble with the concept when voters twice elected the likable Bill Clinton. Meanwhile, many of the conservatives who supported Bush couldn't believe that Americans would vote for Clinton.

Believe it. If Mitt Romney wants to win the Republican nomination, he should worry less about showing that he understands the difference between health care plans and more about convincing average Americans that he understands them.

The opinions expressed in this commentary are solely those of Ruben Navarrette Jr.